test/java/util/Map/BasicSerialization.java

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rev 6813 : 7143928: Optimize empty HashMap and ArrayList
Reviewed-by: mduigou
Contributed-by: Sergey Linetskiy <sergey.linetskiy@oracle.com>, John Rose <john.rose@oracle.com>, Mike Duigou <mike.duigou@oracle.com>

@@ -21,405 +21,201 @@
  * questions.
  */
 
 /*
  * @test
- * @bug 7126277
- * @run main Collisions -shortrun
- * @run main/othervm -Djdk.map.althashing.threshold=0 Collisions -shortrun
- * @summary Ensure Maps behave well with lots of hashCode() collisions.
+ * @bug 7143928
+ * @run testng BasicSerialization
+ * @summary Ensure Maps can be serialized and deserialized.
  * @author Mike Duigou
  */
+import java.io.ByteArrayOutputStream;
+import java.io.InputStream;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.ByteArrayInputStream;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Method;
 import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentSkipListMap;
 
-public class Collisions {
-
+import org.testng.annotations.Test;
+import org.testng.annotations.DataProvider;
+import static org.testng.Assert.fail;
+import static org.testng.Assert.assertEquals;
+import static org.testng.Assert.assertTrue;
+import static org.testng.Assert.assertFalse;
+import static org.testng.Assert.assertSame;
+
+public class BasicSerialization {
+
+    enum IntegerEnum {
+
+        e0, e1, e2, e3, e4, e5, e6, e7, e8, e9,
+        e10, e11, e12, e13, e14, e15, e16, e17, e18, e19,
+        e20, e21, e22, e23, e24, e25, e26, e27, e28, e29,
+        e30, e31, e32, e33, e34, e35, e36, e37, e38, e39,
+        e40, e41, e42, e43, e44, e45, e46, e47, e48, e49,
+        e50, e51, e52, e53, e54, e55, e56, e57, e58, e59,
+        e60, e61, e62, e63, e64, e65, e66, e67, e68, e69,
+        e70, e71, e72, e73, e74, e75, e76, e77, e78, e79,
+        e80, e81, e82, e83, e84, e85, e86, e87, e88, e89,
+        e90, e91, e92, e93, e94, e95, e96, e97, e98, e99,
+        EXTRA_KEY;
+        public static final int SIZE = values().length;
+    };
+    private static final int TEST_SIZE = IntegerEnum.SIZE - 1;
     /**
-     * Number of elements per map.
+     * Realized keys ensure that there is always a hard ref to all test objects.
      */
-    private static final int TEST_SIZE = 5000;
-
-    final static class HashableInteger implements Comparable<HashableInteger> {
-
-        final int value;
-        final int hashmask; //yes duplication
-
-        HashableInteger(int value, int hashmask) {
-            this.value = value;
-            this.hashmask = hashmask;
-        }
-
-        @Override
-        public boolean equals(Object obj) {
-            if (obj instanceof HashableInteger) {
-                HashableInteger other = (HashableInteger) obj;
-
-                return other.value == value;
-            }
-
-            return false;
-        }
-
-        @Override
-        public int hashCode() {
-            return value % hashmask;
-        }
-
-        @Override
-        public int compareTo(HashableInteger o) {
-            return value - o.value;
-        }
-
-        @Override
-        public String toString() {
-            return Integer.toString(value);
-        }
-    }
-
-    private static Object[][] makeTestData(int size) {
-        HashableInteger UNIQUE_OBJECTS[] = new HashableInteger[size];
-        HashableInteger COLLIDING_OBJECTS[] = new HashableInteger[size];
-        String UNIQUE_STRINGS[] = new String[size];
-        String COLLIDING_STRINGS[] = new String[size];
-
-        for (int i = 0; i < size; i++) {
-            UNIQUE_OBJECTS[i] = new HashableInteger(i, Integer.MAX_VALUE);
-            COLLIDING_OBJECTS[i] = new HashableInteger(i, 10);
-            UNIQUE_STRINGS[i] = unhash(i);
-            COLLIDING_STRINGS[i] = (0 == i % 2)
-                    ? UNIQUE_STRINGS[i / 2]
-                    : "\u0000\u0000\u0000\u0000\u0000" + COLLIDING_STRINGS[i - 1];
-        }
-
-     return new Object[][] {
-            new Object[]{"Unique Objects", UNIQUE_OBJECTS},
-            new Object[]{"Colliding Objects", COLLIDING_OBJECTS},
-            new Object[]{"Unique Strings", UNIQUE_STRINGS},
-            new Object[]{"Colliding Strings", COLLIDING_STRINGS}
-        };
-    }
-
+    private static final IntegerEnum[] KEYS = new IntegerEnum[TEST_SIZE];
     /**
-     * Returns a string with a hash equal to the argument.
-     *
-     * @return string with a hash equal to the argument.
+     * Realized values ensure that there is always a hard ref to all test
+     * objects.
      */
-    public static String unhash(int target) {
-        StringBuilder answer = new StringBuilder();
-        if (target < 0) {
-            // String with hash of Integer.MIN_VALUE, 0x80000000
-            answer.append("\\u0915\\u0009\\u001e\\u000c\\u0002");
+    private static final String[] VALUES = new String[TEST_SIZE];
 
-            if (target == Integer.MIN_VALUE) {
-                return answer.toString();
+    static {
+        IntegerEnum[] keys = IntegerEnum.values();
+        for (int each = 0; each < TEST_SIZE; each++) {
+            KEYS[each] = keys[each];
+            VALUES[each] = keys[each].name();
             }
-            // Find target without sign bit set
-            target = target & Integer.MAX_VALUE;
         }
+    private static final IntegerEnum EXTRA_KEY = IntegerEnum.EXTRA_KEY;
+    private static final String EXTRA_VALUE = IntegerEnum.EXTRA_KEY.name();
 
-        unhash0(answer, target);
-        return answer.toString();
-    }
+    public static <K, V> Map<K, V> mapClone(Map<K, V> map) {
+        Method cloneMethod;
 
-    private static void unhash0(StringBuilder partial, int target) {
-        int div = target / 31;
-        int rem = target % 31;
-
-        if (div <= Character.MAX_VALUE) {
-            if (div != 0) {
-                partial.append((char) div);
-            }
-            partial.append((char) rem);
-        } else {
-            unhash0(partial, div);
-            partial.append((char) rem);
-        }
+        try {
+            cloneMethod = map.getClass().getMethod("clone", new Class[]{});
+        } catch (NoSuchMethodException | SecurityException all) {
+            cloneMethod = null;
     }
 
-    private static void realMain(String[] args) throws Throwable {
-        boolean shortRun = args.length > 0 && args[0].equals("-shortrun");
-
-        Object[][] mapKeys = makeTestData(shortRun ? (TEST_SIZE / 2) : TEST_SIZE);
-
-        // loop through data sets
-        for (Object[] keys_desc : mapKeys) {
-            Map<Object, Object>[] maps = (Map<Object, Object>[]) new Map[]{
-                        new HashMap<>(),
-                        new Hashtable<>(),
-                        new IdentityHashMap<>(),
-                        new LinkedHashMap<>(),
-                        new TreeMap<>(),
-                        new WeakHashMap<>(),
-                        new ConcurrentHashMap<>(),
-                        new ConcurrentSkipListMap<>()
-                    };
-
-            // for each map type.
-            for (Map<Object, Object> map : maps) {
-                String desc = (String) keys_desc[0];
-                Object[] keys = (Object[]) keys_desc[1];
+        if (null != cloneMethod) {
                 try {
-                    testMap(map, desc, keys);
-                } catch(Exception all) {
-                    unexpected("Failed for " + map.getClass().getName() + " with " + desc, all);
-                }
-            }
+                Map<K, V> result = (Map<K, V>)cloneMethod.invoke(map, new Object[]{});
+                return result;
+            } catch (Exception all) {
+                fail("clone() failed " + map.getClass().getSimpleName(), all);
+                return null;
         }
-    }
-
-    private static <T> void testMap(Map<T, T> map, String keys_desc, T[] keys) {
-        System.out.println(map.getClass() + " : " + keys_desc);
-        System.out.flush();
-        testInsertion(map, keys_desc, keys);
-
-        if (keys[0] instanceof HashableInteger) {
-            testIntegerIteration((Map<HashableInteger, HashableInteger>) map, (HashableInteger[]) keys);
         } else {
-            testStringIteration((Map<String, String>) map, (String[]) keys);
-        }
-
-        testContainsKey(map, keys_desc, keys);
-
-        testRemove(map, keys_desc, keys);
-
-        map.clear();
-        testInsertion(map, keys_desc, keys);
-        testKeysIteratorRemove(map, keys_desc, keys);
-
-        map.clear();
-        testInsertion(map, keys_desc, keys);
-        testValuesIteratorRemove(map, keys_desc, keys);
-
-        map.clear();
-        testInsertion(map, keys_desc, keys);
-        testEntriesIteratorRemove(map, keys_desc, keys);
-
-        check(map.isEmpty());
-    }
-
-    private static <T> void testInsertion(Map<T, T> map, String keys_desc, T[] keys) {
-        check("map empty", (map.size() == 0) && map.isEmpty());
-
-        for (int i = 0; i < keys.length; i++) {
-            check(String.format("insertion: map expected size m%d != i%d", map.size(), i),
-                    map.size() == i);
-            check(String.format("insertion: put(%s[%d])", keys_desc, i), null == map.put(keys[i], keys[i]));
-            check(String.format("insertion: containsKey(%s[%d])", keys_desc, i), map.containsKey(keys[i]));
-            check(String.format("insertion: containsValue(%s[%d])", keys_desc, i), map.containsValue(keys[i]));
-        }
-
-        check(String.format("map expected size m%d != k%d", map.size(), keys.length),
-                map.size() == keys.length);
-    }
-
-    private static void testIntegerIteration(Map<HashableInteger, HashableInteger> map, HashableInteger[] keys) {
-        check(String.format("map expected size m%d != k%d", map.size(), keys.length),
-                map.size() == keys.length);
-
-        BitSet all = new BitSet(keys.length);
-        for (Map.Entry<HashableInteger, HashableInteger> each : map.entrySet()) {
-            check("Iteration: key already seen", !all.get(each.getKey().value));
-            all.set(each.getKey().value);
-        }
-
-        all.flip(0, keys.length);
-        check("Iteration: some keys not visited", all.isEmpty());
-
-        for (HashableInteger each : map.keySet()) {
-            check("Iteration: key already seen", !all.get(each.value));
-            all.set(each.value);
-        }
-
-        all.flip(0, keys.length);
-        check("Iteration: some keys not visited", all.isEmpty());
-
-        int count = 0;
-        for (HashableInteger each : map.values()) {
-            count++;
-        }
-
-        check(String.format("Iteration: value count matches size m%d != c%d", map.size(), count),
-                map.size() == count);
-    }
-
-    private static void testStringIteration(Map<String, String> map, String[] keys) {
-        check(String.format("map expected size m%d != k%d", map.size(), keys.length),
-                map.size() == keys.length);
-
-        BitSet all = new BitSet(keys.length);
-        for (Map.Entry<String, String> each : map.entrySet()) {
-            String key = each.getKey();
-            boolean longKey = key.length() > 5;
-            int index = key.hashCode() + (longKey ? keys.length / 2 : 0);
-            check("key already seen", !all.get(index));
-            all.set(index);
-        }
-
-        all.flip(0, keys.length);
-        check("some keys not visited", all.isEmpty());
-
-        for (String each : map.keySet()) {
-            boolean longKey = each.length() > 5;
-            int index = each.hashCode() + (longKey ? keys.length / 2 : 0);
-            check("key already seen", !all.get(index));
-            all.set(index);
-        }
-
-        all.flip(0, keys.length);
-        check("some keys not visited", all.isEmpty());
-
-        int count = 0;
-        for (String each : map.values()) {
-            count++;
-        }
-
-        check(String.format("value count matches size m%d != k%d", map.size(), keys.length),
-                map.size() == keys.length);
-    }
-
-    private static <T> void testContainsKey(Map<T, T> map, String keys_desc, T[] keys) {
-        for (int i = 0; i < keys.length; i++) {
-            T each = keys[i];
-            check("containsKey: " + keys_desc + "[" + i + "]" + each, map.containsKey(each));
-        }
-    }
-
-    private static <T> void testRemove(Map<T, T> map, String keys_desc, T[] keys) {
-        check(String.format("remove: map expected size m%d != k%d", map.size(), keys.length),
-                map.size() == keys.length);
-
-        for (int i = 0; i < keys.length; i++) {
-            T each = keys[i];
-            check("remove: " + keys_desc + "[" + i + "]" + each, null != map.remove(each));
-        }
-
-        check(String.format("remove: map empty. size=%d", map.size()),
-                (map.size() == 0) && map.isEmpty());
-    }
-
-    private static <T> void testKeysIteratorRemove(Map<T, T> map, String keys_desc, T[] keys) {
-        check(String.format("remove: map expected size m%d != k%d", map.size(), keys.length),
-                map.size() == keys.length);
-
-        Iterator<T> each = map.keySet().iterator();
-        while (each.hasNext()) {
-            T t = each.next();
-            each.remove();
-            check("not removed: " + each, !map.containsKey(t) );
-        }
-
-        check(String.format("remove: map empty. size=%d", map.size()),
-                (map.size() == 0) && map.isEmpty());
-    }
-
-    private static <T> void testValuesIteratorRemove(Map<T, T> map, String keys_desc, T[] keys) {
-        check(String.format("remove: map expected size m%d != k%d", map.size(), keys.length),
-                map.size() == keys.length);
-
-        Iterator<T> each = map.values().iterator();
-        while (each.hasNext()) {
-            T t = each.next();
-            each.remove();
-            check("not removed: " + each, !map.containsValue(t) );
-        }
-
-        check(String.format("remove: map empty. size=%d", map.size()),
-                (map.size() == 0) && map.isEmpty());
-    }
-
-    private static <T> void testEntriesIteratorRemove(Map<T, T> map, String keys_desc, T[] keys) {
-        check(String.format("remove: map expected size m%d != k%d", map.size(), keys.length),
-                map.size() == keys.length);
-
-        Iterator<Map.Entry<T,T>> each = map.entrySet().iterator();
-        while (each.hasNext()) {
-            Map.Entry<T,T> t = each.next();
-            T key = t.getKey();
-            T value = t.getValue();
-            each.remove();
-            check("not removed: " + each, (map instanceof IdentityHashMap) || !map.entrySet().contains(t) );
-            check("not removed: " + each, !map.containsKey(key) );
-            check("not removed: " + each, !map.containsValue(value));
-        }
-
-        check(String.format("remove: map empty. size=%d", map.size()),
-                (map.size() == 0) && map.isEmpty());
-    }
-
-    //--------------------- Infrastructure ---------------------------
-    static volatile int passed = 0, failed = 0;
-
-    static void pass() {
-        passed++;
-    }
+            Constructor<? extends Map> copyConstructor;
+            try {
+                copyConstructor = (Constructor<? extends Map>)map.getClass().getConstructor(new Class[]{Map.class});
 
-    static void fail() {
-        failed++;
-        (new Error("Failure")).printStackTrace(System.err);
-    }
+                Map<K, V> result = (Map<K, V>)copyConstructor.newInstance(new Object[]{map});
 
-    static void fail(String msg) {
-        failed++;
-        (new Error("Failure: " + msg)).printStackTrace(System.err);
+                return result;
+            } catch (Exception all) {
+                return serialClone(map);
     }
-
-    static void abort() {
-        fail();
-        System.exit(1);
     }
-
-    static void abort(String msg) {
-        fail(msg);
-        System.exit(1);
     }
 
-    static void unexpected(String msg, Throwable t) {
-        System.err.println("Unexpected: " + msg);
-        unexpected(t);
+    @Test(dataProvider = "Map<IntegerEnum,String>")
+    public void testSerialization(String description, Map<IntegerEnum, String> map) {
+        Object foo = new Object();
+
+        Map<IntegerEnum, String> clone = mapClone(map);
+        Map<IntegerEnum, String> serialClone = serialClone(map);
+
+        assertEquals(map, map, description + ":should equal self");
+        assertEquals(clone, map, description + ":should equal clone");
+        assertEquals(map, clone, description + ": should equal orginal map");
+        assertEquals(serialClone, map, description + ": should equal deserialized clone");
+        assertEquals(map, serialClone, description + ": should equal original map");
+        assertEquals(serialClone, clone, description + ": deserialized clone should equal clone");
+        assertEquals(clone, serialClone, description + ": clone should equal deserialized clone");
+
+        assertFalse(map.containsKey(EXTRA_KEY), description + ":unexpected key");
+        assertFalse(clone.containsKey(EXTRA_KEY), description + ":unexpected key");
+        assertFalse(serialClone.containsKey(EXTRA_KEY), description + ":unexpected key");
+        map.put(EXTRA_KEY, EXTRA_VALUE);
+        clone.put(EXTRA_KEY, EXTRA_VALUE);
+        serialClone.put(EXTRA_KEY, EXTRA_VALUE);
+        assertTrue(map.containsKey(EXTRA_KEY), description + ":missing key");
+        assertTrue(clone.containsKey(EXTRA_KEY), description + ":missing key");
+        assertTrue(serialClone.containsKey(EXTRA_KEY), description + ":missing key");
+        assertSame(map.get(EXTRA_KEY), EXTRA_VALUE, description + ":wrong value");
+        assertSame(clone.get(EXTRA_KEY), EXTRA_VALUE, description + ":wrong value");
+        assertSame(serialClone.get(EXTRA_KEY), EXTRA_VALUE, description + ":wrong value");
+
+        assertEquals(map, map, description + ":should equal self");
+        assertEquals(clone, map, description + ":should equal clone");
+        assertEquals(map, clone, description + ": should equal orginal map");
+        assertEquals(serialClone, map, description + ": should equal deserialized clone");
+        assertEquals(map, serialClone, description + ": should equal original map");
+        assertEquals(serialClone, clone, description + ": deserialized clone should equal clone");
+        assertEquals(clone, serialClone, description + ": clone should equal deserialized clone");
     }
 
-    static void unexpected(Throwable t) {
-        failed++;
-        t.printStackTrace(System.err);
-    }
-
-    static void check(boolean cond) {
-        if (cond) {
-            pass();
-        } else {
-            fail();
+    static byte[] serializedForm(Object obj) {
+        try {
+            ByteArrayOutputStream baos = new ByteArrayOutputStream();
+            new ObjectOutputStream(baos).writeObject(obj);
+            return baos.toByteArray();
+        } catch (IOException e) {
+            fail("Unexpected Exception", e);
+            return null;
         }
     }
 
-    static void check(String desc, boolean cond) {
-        if (cond) {
-            pass();
-        } else {
-            fail(desc);
-        }
+    static Object readObject(byte[] bytes) throws IOException, ClassNotFoundException {
+        InputStream is = new ByteArrayInputStream(bytes);
+        return new ObjectInputStream(is).readObject();
     }
 
-    static void equal(Object x, Object y) {
-        if (Objects.equals(x, y)) {
-            pass();
-        } else {
-            fail(x + " not equal to " + y);
+    @SuppressWarnings("unchecked")
+    static <T> T serialClone(T obj) {
+        try {
+            return (T)readObject(serializedForm(obj));
+        } catch (IOException | ClassNotFoundException e) {
+            fail("Unexpected Exception", e);
+            return null;
         }
     }
 
-    public static void main(String[] args) throws Throwable {
-        Thread.currentThread().setName(Collisions.class.getName());
-//        Thread.currentThread().setPriority(Thread.MAX_PRIORITY);
-        try {
-            realMain(args);
-        } catch (Throwable t) {
-            unexpected(t);
+    @DataProvider(name = "Map<IntegerEnum,String>", parallel = true)
+    private static Iterator<Object[]> makeMaps() {
+        return Arrays.asList(
+            // empty
+            new Object[]{"HashMap", new HashMap()},
+            new Object[]{"LinkedHashMap", new LinkedHashMap()},
+            new Object[]{"Collections.checkedMap(HashMap)", Collections.checkedMap(new HashMap(), IntegerEnum.class, String.class)},
+            new Object[]{"Collections.synchronizedMap(HashMap)", Collections.synchronizedMap(new HashMap())},
+            // null hostile
+            new Object[]{"EnumMap", new EnumMap(IntegerEnum.class)},
+            new Object[]{"Hashtable", new Hashtable()},
+            new Object[]{"TreeMap", new TreeMap()},
+            new Object[]{"ConcurrentHashMap", new ConcurrentHashMap()},
+            new Object[]{"ConcurrentSkipListMap", new ConcurrentSkipListMap()},
+            new Object[]{"Collections.checkedMap(ConcurrentHashMap)", Collections.checkedMap(new ConcurrentHashMap(), IntegerEnum.class, String.class)},
+            new Object[]{"Collections.synchronizedMap(EnumMap)", Collections.synchronizedMap(new EnumMap(IntegerEnum.class))},
+            // filled
+            new Object[]{"HashMap", fillMap(new HashMap())},
+            new Object[]{"LinkedHashMap", fillMap(new LinkedHashMap())},
+            new Object[]{"Collections.checkedMap(HashMap)", Collections.checkedMap(fillMap(new HashMap()), IntegerEnum.class, String.class)},
+            new Object[]{"Collections.synchronizedMap(HashMap)", Collections.synchronizedMap(fillMap(new HashMap()))},
+            // null hostile
+            new Object[]{"EnumMap", fillMap(new EnumMap(IntegerEnum.class))},
+            new Object[]{"Hashtable", fillMap(new Hashtable())},
+            new Object[]{"TreeMap", fillMap(new TreeMap())},
+            new Object[]{"ConcurrentHashMap", fillMap(new ConcurrentHashMap())},
+            new Object[]{"ConcurrentSkipListMap", fillMap(new ConcurrentSkipListMap())},
+            new Object[]{"Collections.checkedMap(ConcurrentHashMap)", Collections.checkedMap(fillMap(new ConcurrentHashMap()), IntegerEnum.class, String.class)},
+            new Object[]{"Collections.synchronizedMap(EnumMap)", Collections.synchronizedMap(fillMap(new EnumMap(IntegerEnum.class)))}).iterator();
+    }
+
+    private static Map<IntegerEnum, String> fillMap(Map<IntegerEnum, String> result) {
+        for (int each = 0; each < TEST_SIZE; each++) {
+            result.put(KEYS[each], VALUES[each]);
         }
 
-        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
-        if (failed > 0) {
-            throw new Error("Some tests failed");
-        }
+        return result;
     }
 }